Finding the Fourth Proportional to 1,018.50, 1,404.48 and 664.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,018.50 : 1,404.48 = 664.50 : x
2. Step 2: Convert to fraction form
   1,018.50/1,404.48 = 664.50/x
3. Step 3: Cross multiply
   1,018.50x = 1,404.48 × 664.50
4. Step 4: Simplify right side
   1,018.50x = 933,276.96
5. Step 5: Solve for x
   x = 933,276.96/1,018.50
6. Step 6: Final answer
   x = 916.32